Linings for inner walls of combustion chambers, in particular also those for gas turbines, are known in the art. The combustion chambers are lined with essentially plate-shaped shielding elements which are temperature-resistant, “plate-shaped” describing the basic dimension. The shielding elements may also be designed as hollow elements. So that different or non-stationery heat expansions can be absorbed, gaps are normally left between adjacent shielding elements. Since hot gas originating from the combustion chamber can enter these gaps, this being capable of leading to overheating on shielding elements, holding elements or the combustion chamber wall, it is known to introduce barrier air between the combustion chamber wall and the shielding elements, so that the gaps are shut off against the in draft of hot gas.
Some of the barrier air is required for cooling the shielding or fastening elements. The minimum air consumption is defined by the air quantity necessary for cooling the shielding and fastening elements. Ideally, this air quantity required for cooling should also be sufficient for shutting off the gaps. However, it is necessary to have considerably higher air quantities in order to shut off the technically required gaps (heat expansion stationary and non-stationary, manufacturing tolerances, assembly requirements) between the shielding elements. The air demand therefore depends directly on the gap area.
Furthermore, a pressure and temperature field is formed within the combustion chamber. This pressure and temperature field must be taken into account in the dimensioning of the air demand. Locally higher air quantities are therefore necessary. The proposed flow barrier reduces the gap area and thus allows a considerable reduction in the air demand. Moreover, the air demand is largely uncoupled from the pressure and temperature field, thereby affording a further potential for saving.
The lowering of the air demand has a positive effect on the stability of the burner flames, the effectiveness of the machine and the pollutant emissions and makes it possible to have a further increase in performance, while adhering to maximum given material temperatures.